JPS59500790A - High density printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] High density printed wiring board Technical background of the invention 1 Technical field of invention The present invention relates to printed wiring boards, and more particularly, the present invention relates to printed wiring boards, and more particularly, to Concerning wiring boards with high density of feed-throughvias It is something that

2. Explanation of background technology The number of conductors that can be placed on a layer of a conventional multilayer printed wiring board is It is controlled by the large copper IE wood that forms the terminal.

Each pad and band cluster creates a channel or The position of the printed wiring board is disturbed and as a result, the printed wiring board must be It was necessary to move these conductors to other less dense layers. Traditionally, this kind of Noyad's functions include both electrical and mechanical functions. This electrical function For example, in a pad, an electrical connection to an insertion hole or passageway in a layer can be made. Dust, as much as you can! ll pad can be made small. On the other hand, weaving machine This feature allows the insertion hole with the worst tolerance conditions to be surrounded by the pre-metal, and During the process of making a printed wiring board, the metal inside and adjacent to the insertion hole may be exposed to the etching solution. Therefore, corrosion can be prevented. Therefore, this pad is extremely large. This IE wood must be manufactured with the required thickness to satisfy the electrical function. It needs to be larger than the size, and the standard size is about 20 mils (100 square inches). Ru.

In particular, the traditional process of forming etched insertion holes or passageways So double me 1. A blank having a core made of a dielectric material to be ). To form this insertion hole, a through hole is formed in this blank. This hole is made conductive by sequentially electrodepositing electroless and electroplated copper. It has a tinge to it. Next, apply photoresist material to the surface conductors, islands and pattern across all exposed metal except holes. lastly, Add additional copper using tin-lead solder.1. ．． electrodeposited around and in the drilled holes. The island areas (1 and 1 area) is formed. This photoresist is used as an etching-resistant material. Remove the exposed edges using a sander, and then etch the exposed areas on the surface of the blank. and forming the conductor in the printed wiring board layer. Therefore, above As is clear from There is a function as a means of resisting copper etching in steps and holes. this place In this case, these plated through-holes form a multilayer printed layout d'V7. passages in the inner layer of (vias), then this non-da plating &'i before being superimposed It was peeled off to reinforce the bonding. Also, use a handle around and in the hole. An alternative to de-plating is to photo-etch these holes before etching. It may be surrounded by a resist film like a tent.

To prevent copper build-up in and around the insertion hole during etching. The size of the island area used for this purpose is determined by the following three factors: First of all As an element, suitable from one photoresist pattern to 74 turns of the other. Sufficient tolerance is required to provide accurate registration. .

A typical value for this is 10 mils. For example, due to the tolerance value on the V base, the resist Surrounding these holes with exposed copper will shift the image to one side or the other. It is necessary to The second factor is the need to provide tolerances for the various hole locations. Is Rukoto. This allows compensation for off-center holes and is usually used for this purpose. The pores are approximately 6 to 10 mils larger than the diameter of the pores.

The final element is to replace the island to ensure that the copper in the hole is not etched. There is a need to expand this. Therefore, the predetermined tolerance value is Increase the value by about 4 to 10 mils. As a result, these tolerances and requirements In total, these should form an island area that is 20-30 mils larger than the hole. Ru. Generally, the minimum pore diameter is 135 mils, so the minimum island area is 335 mils. ~435 mils, or 2μ to 3 times the pore diameter.

As a result of these large island areas, conductor density is limited and plated The spacing between through holes is limited by industry standards to about 50 mils (center to center).

Therefore, when increasing the number of conductors, an additional wiring board layer is provided and the device terminations are It is necessary to interconnect a set of However, the number of layers can be reduced and It is desirable to increase the density within the layers.

More recently, hermetic leadless carriers (hermetic leadless carriers) less carrier) for termination purposes between 20 and 25 mil centers. , has been widely used.

This reduced spacing allows for higher densities than can be achieved with conventional techniques. A printed wiring board layer can be realized with

Summary of the invention The present invention avoids the above-mentioned conventional problems by forming island regions. The island area serves only as an electrical connection; It's at least as small. For example, when viewed in cross section, an insert of 8 mil or less A hole or passageway can be formed in the printed wiring board, thereby making the hole (passage) , which can be at least equal to the width of the conductor to be bonded.

To easily form such insertion hole dimensions or passageways, conductive passageway material can be pre-prepared. installed in the openings through the dielectric core of the component wiring board, and furthermore, at the positions of these insertion holes. the copper-plated surface of the printed wiring board. this to expose the back side of the opposing copper foil. Exposed back side during opening like this The foil is overlaid with conductive renost material and is coated with conductive cladding. completely enveloping both the dielectric core and the resistant dist phase material. These conductive Although the cladding, ding and conductive path materials are the same material, the resist material is It is necessary to use a different composition. Therefore, this conductive cladding part This can be removed with, for example, an etching solution, but the conductive Rennost material Etching of the conductive path material can be prevented.

Hills benefit from the invention. For example, plated during etching Large bands are no longer needed as there is no need to consider hole protection.

The dimensions of each insertion hole or passageway should be larger than the dimensions of the conductor to which it is electrically connected. There is no need to make it large (eg, 8 mils or less). Therefore, the conductor Since the channel is not blocked by the insertion hole, the conductor density is greatly increased. Ru. In addition, the spacing between the centers of the insertion passages has been increased from the conventional 50 mils to 25 mils, and the U12 ．． It can be reduced to about 5 mils. This allows any set of element terminations to be connected together. The number of printed wiring layers required to connect can be reduced. Furthermore, the number of terminations per unit area has been increased compared to normal ones. You can make more. of layers required for a given set of interconnects and terminations. Since the number can be reduced, the weight of the entire printed wiring board can be reduced. Also, print arrangement For a given thickness or weight of a wire plate, the number of layers can increase the spacing between layers. A larger electrical impedance is obtained if it can be reduced by

Other objects and advantages can be easily understood from the following description of the embodiments.

Brief description of the drawing Figures 1-12 illustrate the process for forming printed wiring board layers from sheets of dielectric material. This is a diagram to explain the process steps for this material. A conductive plated area or a double plated area as shown in Figure 2a is formed. There is.

FIG. 13 shows a conventional large passage having a /JS small passage formed according to the present invention. FIG. 3 is a diagram showing a layer having a large island region.

FIG. 14 is a cross-sectional view of a plurality of printed wiring board layers formed according to the present invention. , incorporating conventional plated through-holes using the layers shown in Figure 13, for example. Ru.

Detailed description of the invention The starting step of the process is to form a conductive layer at a high density on a multilayer printed wiring board. As for the conductive plated part (cludding) on the negative side or both sides.

using a sheet or blank made of dielectric material with ctaddtng) be able to. FIG. 1 shows a blank 20, which 20Fi, a core 22 of dielectric material and a single plating layer 24 of conductive material thereon. have The core 22 may be made of a conventional dielectric material such as epoxy glass or polyimide. Glass, epoxy Kevlar and polyimide glass can be used. This crap Conventional one ounce copper, approximately 1.4 mil thick, may be used for the padding 24. I can do it. Approximately 5 mils using chemical etching or laser drilling technology. diameter hole or opening 26 from the non-plated surface 28 of the core 22 to the plated surface 30 of the core. It is formed by penetrating the entirety of 22. Cladding 24 is in contact with this plated surface 30. The point to note here is that the dimensions of the opening with a diameter of 5 mils are For illustrative purposes only, the insertion passageway formed may be approximately 135 mils in diameter. The minimum path shall be shown to be at least 25 times smaller than the previous minimum path.

Instead, a double plating bank 20a is adopted, as shown in Figure 2a, and this A dielectric core 22 and double layer claddings 24, 24a are provided on both sides, and An opening 26 may also be formed. Etch this opening or else A hole is formed through the cladding 24a, and after this, a different A hole was drilled through the core 22 using an etching solution to act as a renost. Etch the cladding 24a. If desired, with a laser perforator A hole 26 can also be formed in the core 22, in which case a copper cladding 24h is configured as a reflective mask. After that, Kula 1. When removing the ding 24a , the structure shown in FIG. 2 is again obtained. At this point, hole 26 is approximately 5 mils in diameter (cross-sectional). ). Cladding 24 is exposed by hole 26. This upper layer is indicated by mark 32.

Next, the resist 34 is applied to the cladding 1.0 as shown in FIG. installed on the bottom side of the ding 24. As a result, the exposed portion 32 of this cladding 24 can be It is completely surrounded by electrodeposition with talic resist 36. This metallic cash register For strike 36, gold, two.

kel and tin-nickel, the thickness of which is approximately 0.0001 to 0.0003 inches. (See Figure 4). The dielectric 22 and the resist 34 are other than this puncture. This prevents the parts from being plated.

As shown in FIG. 5, the hole 26 is then completely filled with a conductive material such as a pan. An insertion hole or passage is formed in the core 22 by this. The upper surface of this core 22 Polish the copper-filled area so that it is flush with the top of the hole (see Figure 6). reference).

Next, metallization similar to conductive Renost 36.

The credits 40 are inserted into the copper channels 38 of the surface 28 of the core 22, as shown in FIG. Formed by electrodeposition or deposition on the top surface. These conductive resist materials 36. ’ 400 is extremely thin, i.e. -~2in 1.000 1,000 However, it is displayed quite thickly on the drawing.

As shown in Figure 8, the next process step is to form a copper metallic foil, for example. (foil) 42 sequentially over the surface 28 of the core 22 and over the conductive resist 40. , formed by electroless deposition and electroplating. Next, I tried the Lenost 34. 5. By peeling it off from the padding 24, the structure shown in FIG. 9 is obtained.

Both of these claddings 24.42 will be covered with photoresist in the next step. do. The photoresist is placed in the desired interconnect pattern 44. (See Figure 1θ). Although it is possible to remove the material of Cladding 24.42, Metallic resist 36.40 and photoresist 42 materials cannot be removed. By using an etching solution 24.42% of these claddings can be selectively removed. The resulting product is shown in FIG.

These claddings 24, 42 and conductive insertion passageway material 3B are If the photoresist 44 is completely provided, this photoresist 44 is electrically conductive. Undesired etching of insertion passage 38 in the absence of resist material 36,40 is sufficient to avoid However, the system registration These insertion holes or passageways 38 are therefore at risk of unwanted material removal. It ends up. As a result, good electrical or mechanical connections to these passageways 38 are impeded. It will be done. Therefore, by plating the vias 38 with conductive resists 36, 40, This allows you to compensate for any errors in registration. Wear.

Next, the resist material 44 is removed and the processed print as shown in FIG. A lint printing board layer is obtained. In the same figure, the mutual The connections are indicated by marks 24a and 42a, respectively. These various insertion holes or interconnect 24a to 42a to facilitate interconnection between passageways. and place it at right angles.

Furthermore, insertion holes or passageways and interconnecting conductors manufactured according to the present invention and , it is also possible to combine it with conventional standardized large island areas. like this An example of application is shown in FIG. Layer 50 consists of a dielectric core 52, one of which is A plurality of interconnection conductor lines 54 are provided on the side surface, and these lines 5.46 emails are in normal status. Also on the other side are multiple interconnections. A conductor line 56 is provided and 56 includes a plurality of interconnecting passageways formed in accordance with the present invention. It is electrically connected by 38. In addition, the enlarged GRADO 60 is included. It can also be produced by etching one or both of the . From these claddings were formed the conductor lines 54, 56 mentioned above. child In order to secure space for these expanded island areas 60, conductor lines 54, 56 from a linear arrangement as shown, for example by portions 54a, 56a. Provide each other. Using these enlarged No. 9 pads 60, a multi-layer An insertion hole can also be formed in the printed wiring board 62.

In the same figure, one insertion hole 64 is diagrammatically drawn, and this hole 64 is used for resin penetration. A plurality of layers connected to each other by a processed material 72 (e.g. a pre-impregnated cloth) It extends through 70. Each of these layers 70 is similar to layer 50 shown in FIG. A similar shape and arrangement can also be used. 1, the insertion hole 64 in Fig. 14 is approximated. The area is enlarged by the pad 60a.

As detailed above, only one embodiment of the present invention has been described, but the present invention is not limited to this embodiment. Various modifications may be made that are limited only to these embodiments.

Fig, 1B Procedural amendment February 1S, 1981 Kazuo Wakasugi, Commissioner of the Patent Office 1.Display of the incident PCT/U383100625 2 Name of the invention High density printed glue board 3. Person who makes corrections Relationship to the incident: Patent applicant Name: Hughes Aircraft Kannoya Knee 5, date of amendment order January 31, 1980 Translation of the Revised World, Choice 1, and Submission H (Y!f Permission Usage, Section 184 Moxibustion, Paragraph 1) Director General of the Special Tax Agency, Waka Kazuo Sugi ■International application name PCT/US83/1JO625 3 Patent applicant Note: Location: American Congregation 1, Caliph Surnia, 90245. Ururu Segno Do.

North Cebu 0 Luveda Boulevard 200 Name Hughes Aircraft ・Kan Gunji - Nationality: United States of America ・1 agent Address: Toranomon, 619-ku, Tokyo] No. 26875, No. 17 Mori Building 5, Proposal of amendment Date of release October 28, 1983 Attachment 6 (Inventory of i-documents) (1) 11m Patent Claims 1. Plug in a blank peg insertion path that has an opening and a conductive material inside the opening. When formed in the lint wiring board, these openings allow the insertion passage and its In the manufacturing method for defining these positions, the conductive material is placed almost completely in the opening. A method for manufacturing an insertion passage, characterized in that the insertion passage is provided throughout the body.

2. By surrounding the exposed part of the conductive material with a conductive resist material. This conductive material is provided almost entirely within the opening, and the conductive resist is The material is of a different composition than the conductive material to protect it from the removal process. The method according to claim 1, characterized in that the method comprises:

3. Surround the conductive material in the opening with conductive cladding, and A resist material is provided between the conductive material and the conductive cladding, and the resist material is provided between the conductive material and the conductive cladding. The conductive material has a composition different from that of the conductive material and the conductive cladding. , removing portions of the conductive cladding to form interconnections between the insertion passages; , thereby causing the conductive material to be removed by the conductive Renost material. The method according to claim 1, characterized in that the method is protected from being processed. .

4. Etching the conductive cladding etching with a solution that cannot etch the conductive regimen material The method according to claim 2 or 3, characterized in that:

5. Cut the conductive cladding on one side of the opening in the blank. a first coating of the conductive resist material; deposited in the opening and on the conductive cladding exposed thereby; , the conductive material is placed in the opening and the first resist material comprises the conductive resist material. a second coating of the conductive resist material deposited in contact with the coating; depositing the conductive material on the exposed conductive material on the other 4111 side of the blank. a second electrically conductive cladding on the other side and in front of said blank. 17 in contact with the coating of the second conductive resist material; A method according to claim 3, characterized in that:

6. The dimensions of the opening and the conductive material therein are the same as the dimensions of the interconnection part. 4. The method according to claim 3, wherein the method is formed so as not to be trapped.

Said inserts having a diameter of 78 mils and less and having a maximum center-to-center spacing of 125 mils. A method of manufacturing forming passageways and interconnections between the passageways, wherein said opening a first conductive plate formed in the blank and on a first side surface of the blank; by positioning the opening so that the opening has a diameter corresponding to the diameter of the insertion conductor. and formed at a position corresponding to the position where this insertion conductor should be placed. a first conductive resist material on the first cladding; a first conductive layer with a material in contact with the opening and the cladding; The strike material includes a material different from the first cladding, and includes a conductive material. a conductive material provided in contact with the first conductive resist material within the opening; extends so as to be on a plane substantially on the same level as the second side surface of the blank, This conductive material includes a material different from the first conductive resist material, and the second conductive resist material includes a material different from the first conductive resist material. A conductive resist material is disposed on the conductive material exposed on the second side of the blank. The second conductive resist material includes the conductive material and the first cladding material. a material different from that of the second conductive cladding, the second conductive cladding the second conductive resist material and the second side surface of the blank; The grading includes a material different from the second electrifying Renost material, and the A first lenost material is removed from said first combing and a separate lennost material is removed from said first combing. on the first and second claddings in the turn of the interconnection portion; the separate Rennost material and the first. Protected by a second conductive renost material removing portions of the first and second claddings that are not connected to the interconnection portion; according to claim 1, further comprising forming a resist material and removing a separate resist material. Production method.

8. A core made of a dielectric material with the first conductive material provided on its first side surface. a sheet having a pattern of openings, and a resist material is applied to the sheet having a pattern of openings. the dielectric material provided on the second side surface of the substrate and exposed by the Renost material; and further, the resist material is removed. The method according to claim 1.

9. The step of removing the first and second cladding portions includes the step of removing the first and second cladding portions. Enlarged conductive material of greater than 10 mil diameter between said insertion passages within the ranks. The above 1. A second cladding is formed around this expanded conductive material. forming the interconnection portion, the insert conductor, the expanded conductive material and the shape; Assemble the processed blank with the finished interconnects with other cylindrical wiring board layers. Together, a multilayer printed wiring board is formed, and this is further incorporated into this multilayer printed wiring board. forming a plated through opening extending through and in contact with the enlarged conductive material; 2. A method according to claim 1, further comprising the step of:

10 Printed wiring manufactured by the manufacturing method described in all the claims above Board.

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Claims (1)

[Claims] Inserts with a diameter of 1.8 mils or less and a maximum of 125 mils between centers. Printed wiring board layers having embedded holes or passageways and interconnections therebetween. To form, forming a hole in the blank having a first conductive cladding on a first side; This hole has a diameter corresponding to the diameter of the insertion conductors, and has a diameter corresponding to the diameter of the insertion conductors. a position corresponding to the position where the body is to be placed; Providing a lugist material, providing a first conductive resist material in contact with the cladding within the hole; The first conductive material is a material different from the first material. contains, providing a conductive material in contact with the first conductive resist material within the hole; This conductive material is extended so as to be substantially flush with the second side surface of the blank. The conductive material contains a material different from the first conductive resist material, a second conductive resist on the conductive material exposed on the second side of the plaque; a second conductive resist material, the second conductive resist material includes the conductive material and the first resist material; A material different from that of the latching material is included, and the second conductive clamp is The resist material contains a material different from the second conductive resist material, and the resist material contains a material different from the second conductive resist material. 1. removing the first lurgist material from the cladding; another cladding on the first and second claddings in the turns of the interconnection portion; providing a resist material, the another resist material and the first and second conductive materials; portions of the first and second claddings that are not protected by resist material; forming the interconnection portion; A printed wiring board characterized in that the other resist material is removed. Method of manufacturing layers. 2 In the hole forming step, the sheet having a core made of a dielectric material is by a conductive cladding and another conductive cladding on both sides of it. and the position in the other conductive cladding on only one side of the core. A small hole is formed in the hole, and the conductive cladding created by the small hole is used as a mask to conduct the induction. the hole in the core up to the first conductive cladding on the other side of the electrical body; The method further includes a step of extending the small hole and removing the cluttering caused by the small hole. The manufacturing method according to claim 1, characterized in that: 3. The extending step includes a laser drilling step, and this drilling step includes: It is believed that the cladding by the small holes acts as a reflector of the laser energy. The manufacturing method according to claim 2, characterized in that: 4. In the extending step, the cluttering due to the small holes is covered with a resist mask. The step used as a Claims further comprising the step of: etching a portion of said core The manufacturing method according to item 2. 5. In the step of forming the holes, the sheet having a core of dielectric material is utilizing the first electrically conductive material on a surface; and forming a hole in the hole. providing a resist material on a second side of the core; etching the dielectric material exposed by etching the resist material; Claim 1 further comprising the step of removing the strike material. Manufacturing method described. 6. The step of removing the first and second cladding portions includes etching the first and second claddings from the first and second conductive layers; For non-etchable materials, the area may be etched using a non-etchable solution. 2. The method of claim 1, further comprising the step of: 7. The first and second claddings and the conductive material contain copper. , the first and second conductive resist materials include gold, di-Kel, and tin-nickel. 7. The method of claim 6, further comprising one of: 8 After the conductive material is provided in the hole, the material is polished into the blank. The feature is that a step is further provided to make the surface flat on the same level as the second side surface of the block. The method according to claim 1. 9. The step of removing the separate resist material. After printing, the treated blank is combined with other printed wiring layers to produce multilayer printing. Claim 1, characterized in that a step and a tab forming a wiring board are further provided. How to put it on. 10. The step of removing the first and second cracks and the 7-day portion includes , from these first and second claddings, there are 10 forming an expanded conductive material with a diameter larger than the mill; placing the interconnect around an enlarged conductive material. The method according to claim 1, characterized in that: 11. The insert conductor, the enlarged conductive material and the disposed interconnect portion Combine processed blanks with other printed wiring board layers to create multilayer printed wiring a step forming a plate and in electrical contact with said expanded conductive material; A plated through hole is formed in the multilayer printed wiring board to penetrate this. 11. The method of claim 10, further comprising the step of: ]2. The step of forming an opening in the blank to define the position of the insertion passage, and the aperture while maintaining the dimensions of the aperture and the material therein substantially the same; providing an electrically conductive material to form an insertion passageway in the printed wiring board. Method. 13 The step further includes the step of completely filling the opening with the conductive material. 13. A method as claimed in claim 12, comprising: 14 The filling step includes filling the exposed 74 portions of the conductive material with a different coating with a conductive resist material consisting of a composition of Claim 13 characterized in that the method includes a step of retaining from work. the method of. 15 In forming a printed wiring board with insertion passages and interconnection parts , a conductive material provided in the opening defining the position of the insertion passage; and the conductive material. conductive cladding surrounding the cladding, and between these conductive materials and the cladding. A step is provided to prepare a blank having a conductive resist material provided in the front. The Rennost material is combined with the conductive material and the conductive cladding in different combinations. and further removing portions of the conductive cladding and interconnecting portions. A predetermined step is provided, and the conductive resist material covers all of the conductive material. A printed wiring board manufacturing method characterized in that all parts are removed and preserved. Law. 16 The removing step may include etching the conductive cladding. This technique can be done using a solution that cannot etch the conductive rennost material. Claim 1 characterized in that it includes a step and a step for etching the recording. Section 5 Fertilization method. 17 A step forming the opening in the conductive cladding on one side of the blank. Te, puto, The conductive material is placed within this opening and on the conductive cladding exposed thereby. depositing a first coating υ of a transparent resist material; This conductive material is placed in the opening and in the first part D extending from the conductive resist material. 1 coating in contact with and depositing; the conductive renost material on the conductive material exposed on the other side of the blank; 1 step of stirring the second coating consisting of the material, Furthermore, a layer was placed on the first side of this blank and in contact with the conductive resist material covered with the second conductive resist material. The removing step includes the step of applying a second ductile crack F ink by touching the ink. 16. The method according to claim 15, characterized in that: 18. Forming the opening, forming the conductive material therein, and adjusting its dimensions. further comprising the step of ensuring that the interconnection portion does not exceed the dimensions of the interconnection portion. 16. The method according to claim 15. 19. Supports having opposing surfaces and made of dielectric material and extending between these opposing surfaces. A printed wiring board having a solid insertion passage which is located on the same plane as the other. 20. Further, a conductive material is provided to cover the insertion passage on the opposing surface, and this material has a composition different from that of the material of the insertion passage. The wiring board described in box 19. 21 that the insertion passage has a diameter of 8 mils when viewed in cross section; The wiring board according to claim 19 or 20, characterized in that: 22. The insertion passages are provided with a maximum center-to-center spacing of 25 mils. The wiring board according to claim 19. 23. Further provide a conductor interconnecting the insertion passage, and the dimensions of this passage are as described above. 20. The wiring board according to claim 19, wherein the wiring board is smaller than that of a conductor. Clean -; (no change in content)